Control structure



April 14, 1936.

w. w. STUART 2,03 7,155

CONTROL STRUCTURE Filed Aug. 7, 1933 Patented Apr. 14, use

UNITED STATES PATENT CWFICE (ION'IPROL STRUCTURE William W. Stuart, DesMoinea. Iowa Application August 7, 1933, Serial No. 684.002

4 Claims. (Cl. 200-140) The object of my invention is to provide acontrol structure of very simple, durable and inexpensive construction,whereby a switch or other control element is actuated for moving acontrol member in one direction when one sensitive element is affectedby rising temperature while the other is affected by fallingtemperature, and for moving the control member in the other directionwhen one sensitive member is 0 aflected by falling temperature and theother is ail'ected by rising temperature, or to provide a controloperated from two temperature sensitive elements subject to temperaturesin diiierent locations and serving to actuate the control from oneposition to the other when the temperatures affecting the sensitiveelements reach a predetermined relation.

In such a control, there is no change in the operative position of thecontrol member when the sensitive members are actuated in the samedirection to the same extent.

with this and other objects in view, my invention consists in theconstruction, arrangement and combination of the various parts oi mycontrol structure, whereby the objects contemplated are attained, ashereinafter more fully forth, pointed out in my claims, and illustratedin the accompanying drawing, in which:

Figure l is a sectional view illustrating my con trol member as appliedto a refrigerating system in a building.

Figure 2 is a perspective view showing the control with the operativeparts enclosed in a suitable casing.

Figure 3 is another sectional view illustrating another application ofthe control.

Figure 4 is a diagrammatic showing of a slight- 1y modified form of myinvention; and

Figure 5 is a diagrammatic showing of another form in which theinvention may be embodied.

Construction shown in Figure 1 I have shown in Figures 1 and 3, twopractical applications of my control. In Figure 1, I have shown acooling apparatus in a house adapted to be-actuated for cooling thehouse when the difierence between the outside and inside temperaturesgoes below a certain predetermined relation, and in which the coolingapparatus becomes imperative when that given relation 01' temperaturesoutside and inside is reached.

In the accompanying drawing, I have used the reference numeral II toindicate a suitable casing for holding certain working parts of mycontrol and ail'ording a support thereto: and tar affording a suitablemeans on which the control may be assembled and by which it may bestored, transportedand mounted where desired.

The case I0 has a removable side plate II, which may be fastened inposition by a screw 5 bolt l4. In the case In, there is arranged amovable control member i6 and a pair of temperature sensitive elementsIt. The particular kind of sensitive element and the arrangement thereofare simply illustrative of my invention and 10 other kinds andarrangements might be employed.

In the illustration here used, I use for the movable control member, amercury switch, which has at one end the contact point 20 and 22 con- 15nected with conducting wires 24 and 26 leading to binding posts 21 and28 mounted in the wall of the casing and connected in turn with theconducting wires III and 32. The'sensitive elements here illustrated arethe known metal bel- 2o lows. Extending upwardly from the heads of therespective bellows are ears or the like 34 and 36. These are connectedby a rock bar or cross bar 38, having the upward central extension 40,on which the control member I is mounted as 25 by means of a strap 42.

Connected with the respective bellows are tubes 44 and 46, which have attheir ends the ordinary bulbs 48 and 50. It will be understood, ofcourse, that the bulbs, tubes and bellows con- 30 tain materialexpansible and contractable according to temperature.

The bulb 48 is located within the room 52 and the bulb 50 is locatedwhere it is subject to outside. temperature, 5

One oi the bellows. is provided with adjusting mechanism 54 of anysuitable kind andfwith an indicating finger 5i projecting through a slot58 in the -wall of the casing. The wall of the casing adjacent the slotis provided with gradua 4o tions 60.

I provide for instancein the base 62 below the room 52 a mechanicalrefrigerator oi known construction;- for instance of the type having anexpansion coils; a condenser 65- and a pump 45 it operated by a motor68. The expansion or cooling coil 64 is arranged in a passage 10.

Ari inlet passage 1! permits air to flow from the room 52 to the passage10, and an outlet passage I4 permits air to flow from the passage 50 Itin the room. The air may thus be circulated past the cooling coil 64.

In the passage ll is a fan it operated by a motor 70.

Sue current supply wire leads to the binding post 28. The other currentsupply wire 88 leads to the motor 68 and has a branch 82 leading to themotor '13. The wire 38 leads from the motor 18 to a binding post 21 andhas a branch 84 leading to the motor 68.

Operation of apparatus shown in Figure 1 I shall now describe thepractical operation of my control structure when arranged in theenvironment illustrated in Figure 1.

Let us assume that it is the desire to operate the cooling mechanismwhenever the temperature in the room is less than below the temperatureoutside and to stop the cooling mechanism whenever the temperature inthe room is 10 or more colder than the outside temperature.

The left-hand bellows I8 is adjusted by means of the mechanism 54 tobring the finger 56 to the proper position as illustrated for instancein Figure 2, so as to get the desired result mentioned. It will, ofcourse, be understood that the parts may be adjusted and set foraccomplishing this purpose. That is to say, the left-hand bellows isadjusted so that when the inside temperature rises to the point where itis less than 10 below the outside temperature, the cooling apparatuswill be started.

It will be observed that when both inside and outside temperatures risein the same proportion, the cross bar 38 and the control member I6 willbe raised, but the control member I6 will not be moved to afiect anyoperation. Similarly when the bellows contract equally, there will be nosuch eifect on the control member I6 as to cause it to change from oneoperative position to the other.

However, if the temperature affecting the bulb 48 goes up or thetemperature affecting the bulb 58 goes down until the temperatureaffecting the bulb 48 is less than 10 below the temperature affectingthe bulb 58, the bar 38 and the member I6 will be tilted to bring themercury in the bulb to position for closing the contacts 22 and 28 andthus closing the circuit, whereupon the motor 68 will be energized foroperating the pump 66 and operating the cooling mechanism.

It will be understood that the bellows are so adjusted that suchincreasing of the temperature affecting the bulb 48 with relation to thetemperature affecting the bulb 58 causes expansion of the left-handbellows I8 and thus tends to rock the bar 38 and the member I6 to thecontact closing position illustrated in Figure 1. Similarly, a loweringin the temperature affecting the bulb 58 with relation to thetemperature affecting the bulb 48 causes contraction of the right-handbellows I8 and produces the same result.

It may be mentioned at this time that when the device is inoperative, alowering of the temperature affecting the bulb 48 simply effects afurther contraction of the left-hand bulb I8 and has no effect upon theoperation of the device. Likewisewhen the temperature in the room is 10below the temperature outside, an increase in the outside temperatureeflects an expansion of the right-hand bellows I8, but does not effectany operation of the member I6.

The motor I8 is so connected that it will be energized at the same timeas the motor 68 for operating the fan and thus causing circulationthrough the passage 18 past the cooling coil 64 and into the room 52.

When the temperature in the room 52 drops to the point where it is 10below the temperature outside, the lefthand bellows I8 will havecantracted relatively for causing rocking movement of the bar 38 and themember I6 and for causing the mercury to leave the contacts 2228 forthus breaking the circuit. Should the temperature in the room continueto drop until it is more than 10 below the outside temperature, thecontrol is not afiected.

I am thus able to operate the cooling system so as to maintain thetemperature in the room at a given point below the temperature outside.

The apparatus may be provided with limiting devices so that the room maynot be kept at the predetermined relation to outside temperature wherethat is undesirable.

Construction shown in Figure 3 In Figure 3, I have shown anotherpractical application of my control.

In this figure, I have illustrated a mechanism operated from thecontrol, whereby when the outside air is colder than the air in a house,it will be drawn into and circulated through the. house, and when theoutside air is no colder or is warmer than the air inside, the house, nooutside air is drawn into the house. but a circulation of the air in thehouse is maintained.

I utilize the ordinary unused furnace and the pipes connected therewithfor the circulation of the air. The installation shown in this figureis, of course, intended primarily for summer use.

The control shown in Figure 3 is the same as that shown in Figure 1,except that the control member I6 has contacts 22a and 28a at theopposite end of the bulb from the contacts 22-28, so that the tilting ofthe bulb in either direction closes a circuit for purposes ashereinafter set forth.

In Figure 3, I have shown a building having the rooms 86 and 88 and thebasement 89 and the attic 98.

The building is equipped with a heating system including a furnace 9Ifrom which the heat pipes 92 lead to the rooms 86 and 88. An airconducting passage 94 leads to the lower part of the furnace. Thepassage 94 has an air inlet 96 for permitting intake of outside air andhas intake passages 98 and I88 from the rooms 86 and 88.

For controlling the flow of air from the outside through the inlet 96, Iprovide a damper I82 normally tensioned to closed position by means ofthe spring I84 and connected with a movable core of a solenoid I86.

In the passage 94 between the inlet 96 and the closest of the inlets 98and I88, I place a damper I88 normally tensioned to closed position by aspring H8 and connected with the movable core of a solenoid H2.

The current supply wire H4 is connected with the contacts 22 and 22a andis connected by a branch wire II6 with a motor II8 for operating a fanI28 in the passage 94 between the inlet 96 and the furnace 9 I.

In the ceilings of the rooms 86 and 88 are openings I22 and I24controlled by suitable louvre dampers I26 and I 28, which are yieldinglyten sioned toward closed position by means of the springs I38 and I32and are operatively connected with the movable cores of the solenoidsI34 and In the wall of the attic 98 is an outlet opening I38. Adjacentthis opening is a fan I48 for blowing air out of the attic. The fan I48is operated by a motor I42,

I shall now refer to the various circuits 'for controlling themechanisms above described.

From the motor II8 leads a wire I44, which connects with a wire I45. Thewire I45 is in turn connected with a wire I46, which is the othercurrent supply wire.

Whenever the system is operating by the closing of the main switch nothere shown, the motor H8 and the fan I20 will be in operation.

When the outside temperature aifecting the bulb 50 is below the insidetemperature affecting the bulb 48, the right-hand bellows I8 will becontracted for tilting the bar 38 and the control member I6 to positionwhere the mercury closes the circuit between the contacts 22 and 20. Thecurrent conducting wire II4 has a branch I48 which is connected to thecontact 22.

The contact 20 is connected by a wire I50 with the motor I42. The motorI42 is connected with a wire I52, which is in turn connected with thewire I46.

Operation of apparatus shown in Figure 3 Thus when the circuit is closedthrough the contacts 22 and 20, it is likewise closed through the motorI42 for causing operation of the fan I40 and driving the air out of theattic.

At the same time, the damper I08 is closed by the spring H and there isno circuit through the solenoid II2.

At the same time also, the louvres I26 and I28 are held open by theirsolenoids, which are included in circuit as follows:

A branch wire I54 leads from the wire I45 and a wire I56 leads from thewire I54 to the solenoid I06. In turn, the wire I58 leads from thesolenoid I06 to the wire I50. Thereby when the circuit is closed throughthe points 22 and 20, the solenoid I06 is energized for opening thedamper I02 for drawing in outside air (the cooler air).

Leading from the line I50 to the solenoid I34 is a wire I60 and a wireI62 leads in turn from the solenoid I34 to the wire I46, so that whenthe circuit is closed through the contacts 22 and 20, the solenoid I34is energized for opening the louvres I26.

A wire I64 leads from the wire I50 to the solenoid I36 and a wire I66leads from the solenoid I36 to the wire I46 for thus at the same timeclosing the circuit through the solenoid I36 and opening the louvresI28. Thus it will be seen that when the outside temperature is below theinside temperature, the circulation of outside air through the rooms isestablished.

If on the other hand, the outside temperature rises or the insidetemperature goes down, until they are substantially the same, the arm 38and the member I6 rock to position where the mercury leaves the contactpoints 22 and 20 and closes the circuit between the contacts 20a and22a.

It will, of course, be understood that there is a slight differentialwhich I have not mentioned in describing this operation. In actualpractice, the apparatus is usually set to operate only at suchtemperature relations, as justify putting of the apparatus to work.

When the movement of the member I6 last referred to occurs, the circuitis broken through the solenoid I06 and the solenoids I32 and I36 andthrough the motor I42, and the springs close the damper I02 and thelouvres I26 and I28.

The contact points 2011' and 22a are in circuit with the solenoid I I2in the following manner:

A wire I68 leads from the wire 4 to the contact point 22a. The wire Ileads from the contact 20a to the solenoid II2.

A wire I12 leads from the solenoid II2 to the wire I54 and thence to thewire I46. Thus when the circuit is closed through the points 20a and22a, it is likewise closed through the solenoid II2 for opening thedamper I08 for causing a circulation of the air in the rooms 86 and 88.By removing the air duct between the damper I02 and the motor III, thewhole basement may be utilized as a plenum chamber.

Many other applications of my control may be made. It is adapted for usewherever it is desired to actuate a control from one position to anotherwhen the temperatures affecting the sensitive elements reach apredetermined relation, which re lation may be varied considerably asmay be seen from the foregoing illustrations.

It will, of course, be understood that modifications may be made in manyrespects in the elements used and in the construction and arrangement ofparts of my control without departing from the essence of my invention.For instance, both of the temperature sensitive bellows devices orwhatever may be used as substitutes therefor may be made adjustable.

It is obvious that my control may be used with a great many differentkinds of other limiting devices or controls. For instance in theapplication shown in Figure 3,whileltmaybe desirable to draw cooleroutside air under ordinary circumstances, it may likewise be importantunder certain circumstances to put on a limit control, which will shutdown the equipment independently of my control, when the temperature inthe house reaches some predetermined low limit, as for example 60.

Other instances might be given, but these will illustrate the greatvariety of possible uses to which a control of this kind may be put andof situations in which it may be used. Likewise any compensatingadjustments desired may be provided in the control mechanism.

Again it is readily possible to arrange the mechanism between thesensitive elements and the control member I6 in such manner that thecontrol member is not bodily moved but is tilted at the proper times inthe relative movements of the sensitive elements, as illustrateddiagrammatically in Figure 4.

So also the control may be arranged to slide the control member, asillustrated diagrammatically in Figure 5.

The control member may be made to operate a valve or other mechanisminstead of closing a switch.

The mechanism could be arranged to maintain room temperature aboveoutside temperature if desired. The outside temperature affecting theoutside sensitive element may be outdoor air or air in another room orplace.

The control may be used for keeping other fluids as well as airsurrounding chemicals, ceramics or other products or materials cooler orwarmer than the objects cooled or warmed by the fluids.

The device shown in Figure 3 could be used omitting the fan I40, orwhere there is no desire to recirculate the air in the room, the fan I20may be omitted.

I claim as my invention:

1. In a control, a casing having an opening in its wall, an expansiblebellows mounted in the casing for adjustment to a variety of positions,means outside the casing for effecting such adjustment, means associatedwith such bellows and projecting through the opening for indicating thecondition of adjustment of the bellows, a second expansible bellows inthe casing, temperature sensitive elements located in diflerent placesand operatively connected withthe respective bellows, a switch, andmeans interposed between the switch and the two bellows for operatingthe switch in accordance with the relative movement of the bellows.

2. In a control, a casing having an opening in its wall, an expansiblebellows mounted in the casing for adjustment to a variety of positions,ex-

pansible and contractible according to temperature at a given location,means outside the casing for efiectiug such adjustment, means associatedwith such bellows and projecting through the opening for indicating thecondition of adjustment or thebellows, a second expansible bellows inthe casing, expansible and contractible according to temperature atanother location, a switch, and

, means interposed between the switch and the two bellows for operatingthe switch in accordance with the relative movement of the bellows.

3. In a control, a casing, having an opening in its wall, a temperaturesensitive device mounted in the casing for bodily adjustment to avariety of positions subject to the temperature at a given location andinherently movable in accordance with variations in temperature, means(or eifecting such adjustment, means associated with such device andvisible by reason of the opening for indicating the condition ofadjustment of the device, a second temperature sensitive device in thecasing subject to the temperature at another given location andinherently movable in accordance with variations in temperature, aswitch, and means interposed between the switch and the two devices foroperating the switch in accordance with the relative movements of thetwo devices induced by temperature changes.

4. In a control, a casing having an opening in its wall, an expansiblebellows mounted in the casing for adjustment to a variety of positions,means forv effecting such adjustment, means associated with such bellowsand visible by reason of the opening for indicating the condition ofadjustment of the bellows, a second expansible beilows in the casing.temperature sensitive elements located in different places andoperatively connected with the respective bellows, a switch, and meansinterposed between the switch and the two bellows for operating theswitch in accordance with the relative movement of the bellows.

WILLIAM W. STUART.

